In recent years, cell stacks in which a plurality of fuel cells that generate electrical power using a fuel gas (hydrogen-containing gas) and an oxygen-containing gas (air) are connected together have been proposed as next-generation energy sources. Furthermore, various types of fuel cell modules in which a cell stack is housed in a housing container as well as various types of fuel cell devices in which such fuel cell modules are housed in an external case have also been proposed (see Patent Document 1, for example).
One proposed example of such a fuel cell device includes an igniter configured to ignite exhaust gas exhausted from the fuel cells, a combustion catalyst that treats combustion gases after combustion, and a treated exhaust gas temperature sensor configured to measure the temperature of the exhaust gas after being treated by the combustion catalyst, and the like. Here, when the temperature of the treated exhaust gas as measured by the treated exhaust gas temperature sensor is not lower than a prescribed temperature, the igniter is configured to start operation (see Patent Document 2, for example).